The present invention relates to a curing agent for an epoxy resin, which is chemically stable at room temperature, prepared by forming a cyclodextrin clathrate compound of a compound which is reactive with an epoxy group, and a method for curing an epoxy resin using said curing agent.
An epoxy resin which is liquid or thermoplastic at room temperature can be converted into a thermosetting solid by reaction with a compound which is reactive with an epoxy group (a curing agent for an epoxy resin). Curing of an epoxy resin for applications is therefore effected in such a manner that an uncured epoxy resin and a curing agent are separately stored until they are mixed at the time of application.
Primary and secondary amines, amine complex compounds, organic acids and anhydrides thereof, alcohols, phenols, and the like have been used conventionally as the curing agent for an epoxy resin. These curing agents have, however, disadvantages from the viewpoints of treatment or operation because many of them are chemically unstable, volatile, highly toxic to human bodies, or difficult to homogeneously mix or disperse in an epoxy resin (see Japanese Patent Publications No. 9838/1975, No. 27760/1978, and No. 47837/1975).